In recent years, there have been made attempts to apply, to work machines, comprehensive abnormality diagnosis in which the result of an oil analysis by human hand or the result of visual determination is added to information on sensed values of various kinds of sensors provided in the work machines including hydraulic excavators, dump trucks, wheel loaders, forklifts, cranes, and so forth.
For example, in Patent Document 1, a system is disclosed that discriminates the abnormality level of a construction machine based on a combination of all or any two pieces of first construction machine information sensed and collected by a sensor group (for example, sensors of engine revolution speed, engine hydraulic pressure, oil temperature, and blow-by pressure) provided in the construction machine, second construction machine information collected by analyzing oil extracted from the construction machine by a serviceman (oil analysis information), and third construction machine information collected through visual determination of the construction machine by a serviceman (visual information).